Snap action breaker with housing

ABSTRACT

Disclosed is a circuit breaker incorporating a snap action switch. The breaker incorporates a simplified toggle mechanism and one or more of the breakers may be combined with one or more similarly constructed power switches to form a novel multifunction modular package.

[ Apr. 23, 1974 United States Patent 11 1 Harper et a1.

[ SNAP ACTION BREAKER WITH HOUSING 3 395,372 7/1968 Opad 3,488,609 11970 St k [76] Inventors: George S. Harper, 423 Lmden Ave, 3,164,700151965 Bsdeesschatzw Cambndge, 21613; John 3,305,806 2/1967 RichardShand, RFD No. 4, Easton,

Primary Examiner1-1aro1d Broome [22] Filed: Nov. 6, 1972 Attorney,Agent, or Firm-LeBlanc & Shur [21] App]. No.: 303,954

ABSTRACT [5 1 U S Cl 335/188 335/191 Disclosed is a circuit breakerincorporating a snap action switch. The breaker incorporates asimplified toggle mechanism and one or more of the breakers may becombined with one or more similarly constructed power switches to form anovel multi-function modular package.

References Cited UNITED STATES PATENTS 9 Claims,

Kussy et 17 Drawing Figures FATENTEUAPR23 m4 "55.808848 SHEET 1 [IF 7FIG. I

EATENTEDAFR 23 1974 SHEET 5 OF 7 RATENTEDAPR 23 law 3 806; 848

SHEET 6 0F 7 FIG. l2

FIG. l3

2ATENTEDAPR2319Y4 $806548 SHEET 7 [1F 7 FIG. l6

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SNAP ACTION BREAKER WITH HOUSING This invention relates to a circuitbreaker of simplified and inexpensive construction incorporating a snapaction switch operating mechanism. It is also directed to an arrangementfor assemblying a plurality of circuit breaker poles and/or switches toprovide a simplified circuit breaker package having increasedversatility.

Most conventional magnetic type electrical circuit breakers do notincorporate a snap action device for opening and closing the circuitbreaker contacts. As a result, they have the disadvantage that they donot exhibit the increased mechanical and electrical life which as iswell-known accompanies snap action electrical current switching. Inaddition, their failure to open and close with a snap action has in thepast limited the magnitude of the current which can be switched withmost conventional circuit breakers. Attempts to increase a circuitbreaker life and to increase the current handling capability of thecircuit breaker have resulted in expensive operating mechanismssubstantially increasing the overall cost of the breaker.

The circuit breaker of the present invention is provided with a novelspring assembly for opening and closing the circuit breaker contactswith a spring or snap action. As a result, the circuit breaker exhibitsmany of the desirable features of a switch while at the same timeproviding over current protection. Because of the snap action feature itis possible to construct the circuit breaker with a simplified and lessexpensive operating mechanism or toggle, thus substantially reducing theoverall cost of the device. Furthermore, by substituting for thecollapsible toggle a simplified rigid link and eliminating theovercurrent elements of the breaker, it is possible to provide aninexpensive mechanical switch fully compatible in design, constructionand appearance with a circuit breaker. This lends itself to a uniquepackaging system wherein several independent mechanisms be they breakersor switches can be combined in a single housing. Since the switch andcircuit breaker housings are identical, the package appearance isexcellent and the assembly is susceptible to a variety of mountingarrangements. In addition to a versatile package assembly, the modularcircuit breaker and switch construction make it possible to supplyindividual modules to the user which he can assemble as required. Anydesired mix of breakers and/or switches can be assembled up to apractical limit of six or more.

Because of the versatility described above the present invention makespossible an assembly in which power switches and overload switches canbe combined in one package. Each module includes a snap out handlepermitting a change in handle color and if desired a light emittingdiode may be incorporated in the handle to provide illumination.Finally, with the snap switch action the handle feel of the breaker isimproved in such a way as to enhance its commercial acceptability to thetrade.

In the present invention the'contact bar carrying the movable contact ofthe circuit breaker is connected to one end of a coil tension springwhich acts as an over center spring to snap open and snap closed thecircuit breaker contacts. One end of the movable contact bar is pivotedto a' movable actuator or carrier rotatably mounted on the circuitbreaker frame and having an extension pivoted or pinned to the actuatingmechanism or toggle mechanism of the circuit breaker. Movement of thetoggle mechanism either during overcurrent collapse or under theinfluence of the circuit breaker handle during manual operation rotatesthe carrier causing the pivotal support for the contact bar to passthrough the over center plane of the tension spring. During initialmovement of the carrier the contacts remain closed due to the closingforce of the over center spring and the movable contact only undergoes asmall rolling and wiping action against the stationary contact. However,when the support point or contact bar pivot moves through the overcenter plane the coil spring exerts an opening force on the contact barcausing it to snap open under the influence of the tension spring.Similarly, when the handle is moved to the closed position, the togglemechanism acts to rotate the carrier in the opposite direction where thesupport point or pivot point for the contact bar again passes throughthe over center plane of the tension spring changing the force exertedby the spring from an opening force to a closing force and immediatelycausing the contacts to snap closed.

The snap closure force exerted by the over center spring eliminates theneed for any application of pressure by the toggle to the contact bar inorder to keep the contacts closed. As a result, simplified togglemechanisms may be employed while at the same time insur- I ing thatadequate closure forces will be at all times exerted on the movablecontact. Similarly, the snap closure feature makes it possible tosubstitute a rigid link for the toggle actuating mechanism so that thesame basic structure may be employed in a similar configuration as asimple snap action switch. The basic structure may be manufactured withthe same overall configuration as individual modular units and these maybe combined in single multi-pole type packages to provide a package orassembly which exhibits both snap action switching and over currentprotection features.

It is, therefore, one object of the present invention to provide animproved circuit breaker incorporating a snap acting movable contact.

Another object of the present inventionis to provide an improvedelectro-magnetic circuit breaker capable of switching increased current.

Another object of the present invention is to provide an over currentprotection device which also may be used as a snap action switch.

Another object of the present invention is to provide a simplified andinexpensive switch construction which may be used with electricalcircuit breakers.

Another object of the present invention is to provide a modular packageassembly incorporating both circuit breakers and switches.

Another object of the present invention is to provide an improvedmagnetic circuit breaker incorporating a simplified and less expensivetoggle actuating mechanism for the movable contact bar of the circuitbreaker.

Another object of the present invention is to provide an improvedcircuit breaker incorporating a light emitting diode display device inthe operating handle.

Another object of the present invention is to provide an improved moduleconstruction which may be used both for over current protection andpower switching.

These and further objects and advantages of the invention will be moreapparent upon reference to the following specification, claims andappended drawings wherein:

FIG. 1 is a front elevation of a snap acting circuit breaker constructedin accordance with the present invention and with parts broken away andparts omitted to illustrate the internal operating mechanism of thebreaker.

FIG. 2 is an end view of the circuit breaker of FIG. 1.

FIG. 3 is a perspective view of the snap switch contact assembly forminga part of the circuit breaker of FIGS. 1 and 2.

FIG. 4 is a perspective view of a portion of the collapsible togglemechanism of the circuit breaker of FIG. 1.

FIG. 5 is a view of the circuit breaker of FIG. 1 showing it in theclosed position.

FIG. 6 is a view of the circuit breaker of FIG. 1 showing it in the tripfree position.

FIG. 7 is a perspective view of the housing or module for the circuitbreaker of FIG. 1 and showing a display diode in the circuit breakerhandle.

FIG. 8 is a side view of the circuit breaker handle incorporated in themodule of FIG. 7.

FIG. 9 is a rear view of the circuit breaker handle illustrating themanner of mounting the light emitting display diode.

FIG. 10 is a side view of a complete module with parts broken away toillustrate the manner in which the handle is assembled in the module.

FIG. 11 is a partial cross section through the module again illustratingthe handle construction.

FIG. 12 shows a modified construction in which a single housingincorporates three independent mechanisms constructed in accordance withthe present invention.

FIG. 13 shows a power switch constructed in accordance with the presentinvention.

FIG. 14 is a front view showing the manner in which individual modulesof the type illustrated in FIG. 7 may be assembled to form a package.

FIG. 15 is a side view of the assembly of FIG. 14.

FIG. 16 is anend view of the module assembly of FIGS. 14 and 15 and FIG.17 illustrates a modified toggle mechanism which may be incorporatedinto the circuit breaker of FIG. 1.

Referring to the drawings, the novel circuit breaker of the presentinvention is generally illustrated at 10 in FIGS. 1 and 2. The circuitbreaker is illustrated in FIG. 1 in the contacts open or off position.The circuit breaker 10 comprises a housing of suitable electricalinsulating material such as plastic or the like with the lower portionor housing base illustrated at 12. Passing through base 12 of thehousing are a pair of terminals 14 and 16 by means of which the circuitbreaker is electrically connected to an external circuit to be switchedand/or protected against an over current. Terminal 16 is bent over as at18 and mounted on this portion of the terminal is the stationary circuitbreaker contact 20. Terminal 14 is connected by an electrical lead 22 toone end of an over current coil 24. The coil is mounted on a coil frame26 and in the preferred embodiment surrounds a delay tube a portion ofwhich is illustrated at 28. The other end of the coil is connected by aflexible lead 30 to an electrically conductive carrier 32 and by way ofa movable contact bar 34 to the movable contact 36 mounted on thecontact bar. When electrical contacts 20 and 36 close or engage, anelectrical circuit is completed between terminals 14 and 16 by way ofthe over current coil 24.

The coil support frame 26 is in turn supported from a main framegenerally indicated at 38 comprising a pair of spaced, flat parallelplates 40 and 42 joined by a plurality of pins, two of which areillustrated at 44 and 46 in FIG. 1. As best seen in FIG. 2 a handle link48 is pivoted about pin 46 so that it is free to rotate about this pin.The inner end of the handle link 48 is pivoted by a pin 50 as best seenin FIG. 1 to the other end of a collapsible toggle generally indicatedat 52. The toggle comprises an upper link 54 having its lower endtelescopically received within the upper end of a lower link 56. Carriedby lower link 56 is a toggle latch 58 having an extension 60 turned overto form a trip tab 62.

Supported within the main frame is an armature 64 having an extension 66which extends over to adjacent a pole piece 68 of the over current coil24. Armature 64 is pivoted to rotate about a pin 70 and includes acounterweight 72 and a toggle trip extension 74. When an over currentpasses through coil 24 armature extension 66 is attracted to the polepiece 68 and the armature 64 rotates about pin 70 so that extension 74engages and moves trip tab 62 releasing the trip sear permitting thetoggle to collapse under the influence of a toggle spring (not shown) ina well-known manner. This causes contacts 20 and 36 to separate to openthe circuit between terminals 14 and 16.

The details of the latch mechanism 58 are illustrated in FIG. 4. Thelatch comprises a pin 76 rotatably mounted in lower toggle link 56 towhich is attached the latch extension 60 and tab 62. Sear pin 76 is cutaway or notched as at 78 to a semicircular cross section so that whenrotated in the counterclockwise direction as viewed in FIG. 1 it clearslink 54. This link is provided with a cooperating groove 80 whichnormally receives a portion of pin 76 adjacent notch 78 so that with thepin 76 received in the notch link 54 cannot further telescope into link56 to collapse the toggle. However, when tab 62 and pin 76 to which itis attached is rotated in a counterclockwise direction under the urgingof armature extension 74, pin 76 rotates into a position such that itclears groove 80 and upper link 54 is free to further telescope intolower link 56 to collapse the toggle.

Lower toggle link 56 is connected by a pivot pin 82 to a snap switchassembly generally indicated at 84 and illustrated in perspective inFIG. 3. More specifically, pin 82 connects the toggle link to a carrier86 comprising side plates 88 and 90 joined by an integral top plate 92.Flexible lead 30 is preferably soldered to the top plate 92 of thepreferably brass carrier 86. Carrier 86 includes a pair of upwardlyextending tabs 94 and 96 apertured as at 98 and 100 to receive pin 82.Side plates 88 and 90 include downward extensions 102 and 104 which haveturned over portions at their lower ends defining outward extensions or.wings 106 and 108. The ends of the carrier plates 88 and 90 are turnedover as at 110 and 112 and these ends are provided with grooves 114 and116'for receiving and pivotally supporting the ends of contact bar 34.

Contact bar 34 comprises an outer end 118 on the under side of which ismounted the movable contact 36. This end is provided with an aperture120 as best seen in FIG. 3 through which passes and is hooked one end ofa coil tension spring or over center spring 122. A similar hook 124passes around and secures the other end of spring 122 to the stationarycross pin 44. The other end of contact bar 34 is bifurcated to define acentral slot 126 as best seen in FIG. 2 between the spaced contact barlegs 128 and 130. The extreme ends of these legs are received in thegrooves 114 and 116 of the turned over ends 110 and 112 of carrier 86 sothat the contacting edges of contact bar 34 in the grooves act as pivotpoints about which the contact bar 34 may pivot in relation to carrier86. Spring 122 under tension retains the edges of contact bar legs 128and 130 securely retained in the groovesjAt the same time, carrier 86 isfree to pivot relative to the main frame 38. As best seen in FIG. 1 eachof the main frame side plates 40 and 42 is provided with a curved cutoutportion such as that illustrated at 136 in FIG. 1 against which bear therear edges of the carrier projections or wings 106 and 108. Again,spring 122 under tension urges the carrier wings into engagement withthe cutout in the main frame so that the contact points of the wingswith the main frame cutout portions form pivot points for pivotalmovement of carrier 86 relative to the frame. The frame is positioned bya pair of projections on each of the side plates such as the projection138 engaging the edge of a pair of bosses in the housing base 12 such asthat illustrated at 140 in FIG. 1.

FIG. 5 shows the circuit breaker of FIG. 1 in the closed position; thatis, with the movable contact 36 of the contact bar 34 engaging thestationary contact 20.

In FIG. 5 the handle link 48 has been moved in a clock-.

wise direction and a force has been exerted on the contact bar 34 by wayof toggle links 54 and 56 to close the contacts and complete the circuitthrough coil 24 by way of terminals 14 and 16. FIG. 6 shows the circuitbreaker 10 in the trip free position. In the position illustrated inFIG. 6 the trip tab 62 has been rotated in a counterclockwise directionby the armature extension 74 releasing the sear illustrated in FIG. 4and permitting the toggle to collapse. In FIG. 6 the toggle is showncollapsed with the link 54 fully telescoped into link 56, opening thecontacts and 36 and interrupting the electrical current flow throughcoil 24.

In operation, FIG. 1 shows the contacts in the open position with theover center spring 122 holding them open. In thisposition the pivotpoint of the contact bar 34 formed by the heel of the contact barengaging in the actuator grooves 114 and 116 is below the central planeof the over center spring so that the resulting force exerted by thespring on the contact bar is in an open direction. In FIG. 5 handle link148 has been manually moved to a closed position and a first force hasbeen exerted through the toggle and by way of pin 82 on the carrier 86causing the carrier to rotate in a clockwise direction from the positionof FIG. 1 about the pivot point for the carrier defined by theengagement of the wings 106 and 108 with the curved cutouts 136 in themain frame 38. At a predetermined point of rotation of the carrier 86 bythe pin 82 the carrier is rotated sufficiently in a clockwise directionsuch that the heel of the contact bar 34 passes through the horizontalcentral plane of the spring and when this happens the force exerted bythe spring on the contact bar 34 changes from an opening force to aclosing force causing the contact 36 to snap into engagement withstationary contact 20. During initial rotation of the carrier, beforemovement through the over center plane of its heel support, movement ofthe contact 36 is minimal.

When the contacts are manually open the operation is just the reverse,i.e., the force exerted through the toggle mechanism by pin 82 on thecarrier 86 is in a counterclockwise direction causing the contact barheel support grooves of the carrier to move back through the over centerplane so that when they pass through this plane the contact forcebecomes an opening face and the contacts snap open. Again, initialmovement of contact 36 is minimal but the contact does undergo a slightrolling and wiping action before snapping open which action providesimproved electrical continuity through the contacts when they are laterclosed. The operation is essentially similar when the toggle is tripped,i.e., the toggle mechanism collapses under the influence of a togglespring (not shown) in a well-known manner with pin 82 pulling on thecarrier 86 to rotate in a counterclockwise direction passing the heelsupport grooves through the over center plane to cause contact 36 tosnap open from stationary contact 20 under the opening force of the overcenter spring.

FIG. 7 shows a portion of a circuit breaker housing 142 for the circuitbreaker 10 of FIG. 1. Mounted on the front face 144 of the housing is arocker actuator or handle 146 with on and off indicia printed onit.'Carrier by the center of the handle and projecting slightlyoutwardly from it is an indicator light 148 in the form of a lightemitting diode.

FIG. 10 illustrates the housing 142 as a two-piece construction andcomprising the base 12 previously described telescopically received in ahollow body 150. If desired body 150 may be provided with extensions 152and 154 having roughened or serrated ends 156 and 158 which cooperatewith a flange 160 for mounting the circuit breaker module in a panel asmore fully shown and described in assignees copending application Ser.No. 172,632 filed Aug. 18, 1971. Body 150 is preferably made ofresilient electrically insulating plastic material and is provided witha plurality of apertures 162 which receives tabs 164 extending outwardlyfrom base 12 to securely lock the base and body together to form theunitary housing 142. It is understood that the circuit breaker mechanismis initially mounted on the base 12 and the base is then slid into body150 until the tabs 164 pass into apertures 162 locking the two partstogether.

Rocker actuator or handle 146 is provided with a pair of L-shapedgrooves one of which is illustrated at 166 in FIG. 10 which receivescorresponding stub pins 168 and 170 which extend inwardly from the bodyand into the grooves of the handle actuator as best seen in FIG. 11which is a partial cross section taken along line 1 1-11 of FIG. 10.Handle actuator 146 is additionally provided with slots such as slot 170in FIG. 10 which slide overand receive a pin 17 2 passing through theapertures 174 of handle link 148. When rocker handle 146 is manuallyrocked back and forth the handle link 148 moves between the opened andclosed positions illustrated in FIGS. 1 and 5, respectively.

FIGS. 8 and 9 show the details of the construction of rocker handle 146.FIG. 8 is a side view and FIG. 9 is a rear or inside back view of therocker handle. It is preferably made of a suitable electricallyinsulating plastic material and is provided with a central cavity 174adapted to receive the ends of a pair of electrical leads 176 and 178.These flexible leads provide electrical connection to the light emittingdiode 148 projecting from the cavity 174 through a suitable aperture inthe rocker so that it is viewable from the front surface 180. The lightemitting diode is secured in the aperture in the rocker handle by asuitable adhesive of electrically insulating material such as epoxy orthe like as indicated at 182 in FIG. 9. If desired, a current limitingresistor (not shown) may be connected in series with one of the leads176 and 178 to prevent excessive current flow through the light emittingdiode 148. It is understood that the diode forms an indicator light andby way of example only may be used to provide an optical indication asto whether the circuit breaker contacts are opened or closed. It may beused with an auxiliary switch of the type shown and described inassignees U.S. Pat. No. 3,501,606.

As previously indicated, the structure of the present invention readilylends itself to a variety of packages or module assemblies. FIG. 12shows a modified housing construction 184 in which three switching typecircuit breakers l3 constructed in accordance with the present inventionand more particularly in accordance with the mechanism illustrated in FIG. 1 may be combined in a single housing with the respective actuators186, 188 and 190. Alternatively, one or more of the actuators mayoperate a switch construction of a type shown in FIG. 13.

FIG. 13 shows a switch constructed in accordance with the presentinvention. In FIG. 13 like parts bear like reference numerals and theswitch generally indi cated at 184 in FIG. 13 comprises the main frame38, handle link 48, actuating pin 82, stationary contact 20, movablecontact 36, contact bar 34, carrier 86 and over center spring 122. Theswitch 184 is in all respects identical to the circuit breaker of FIG. 1with the ex-' ception that the over current apparatus including the coiland armature have been omitted and a single rigid link 186 issubstituted for the toggle mechanism 52. The switch 184 of FIG. 13exhibits the same snap opening and snap closure features as the circuitbreaker 10 of FIG. 1 when the actuator handle 48 is moved between theposition illustrated in FIGS. 1 and 5. Thus, it is seen that the presentinvention provides a construction which can be used as a circuit breakerand by a minimum of modification as a simple snap acting switch, bothmotable in the same housing such as the housing 142 of FIG. 7 or bothincorporated in a single housing such as the housing 184 in FIG. 12 andboth operable by means of the same type of actuator such as the actuator142 or the actuators 186, 188 and 190 of FIG. 12.

FIGS. 14, and 16 show a preferred packaging assembly in which circuitbreakers of the type illustrated in FIG. 1, switches illustrated in FIG.13 or both may be combined as individual modules into a multi-moduleassembly. FIG. 14 shows a four module assembly generally indicated at196 comprising a circuit breaker 198 and three switches 200, 202 and204. Both the circuit breaker 198 and all three switches 200, 202 and204 are mounted in identical housings 142 of the type previouslydescribed and the circuit breaker 198 has an operating mechanism of thetype illustrated in FIG. 1 and the switches 200, 202 and 204 each haveoperating mechanisms of the type illustrated in FIG. 13. The modules aremounted between end plates 206 and 208 to form the complete package 196.The right-hand end plate 208 has a pair of projections indicated bydashed lines at 210 and 212 and the left-hand plate 206 hascorresponding holes indicated by dashed lines at 214 and 216. Each ofthe modules is provided on its right side as illustrated in FIGS. 14 and15 with holes 218 and 220 for receiving corresponding 'pins, the switch204 illustrated in FIG. 16 receiving the pins 210 and 212 of end plate208. On the left-hand side each module is provided with pins 222 and 224corresponding to the pins 210 and 212 of end plate 208. The pins 222 and224 on the last module, i.e., circuit breaker 198, are received in theholes 214 and 216 in the left-hand end plate 206. The cooperating pinsand holes act to align and to retain the assembly together. By using thepin-recess system molded integral with the module housing and end plate,additional parts such as nuts and screws and the like are not required.The pins are preferably split to permit a tight interference or frictionfit in the aligned recess on hole of the next module.

FIG. 17 shows a modified toggle link construction which may besubstituted for the toggle mechanism 52 in the circuit breaker ofFIG. 1. The latch pin 58 and sear pin 76 are of the same construction aspreviously described. An upper link 232 in FIG. 17 which replaces thelink 54 in the mechanism of FIG. 1 is provided with an outwardlyextending cam 234 which bears on the sear pin 76 and keeps the upperlink 232 rigid with respect to the lower link 234 in FIG. 17 whichreplaces the lower link 56 in the mechanism of FIG. 1. Upper link 232 ispivotally joined to lower link 234 in FIG. 17 by a pin 236 which passesthrough the links. When latch 58 is rotated, the slot in sear pin 76clears the cam 234 permitting the toggle mechanism 230 to collapsethrough rotation of upper link 232 about pin 236 in the direction of thearrow 238 in FIG. 17. Again, the collapsible toggle mechanism 232 is arelatively simplified and inexpensive construction and this is madepossible by the snap switch feature of the circuit breaker of FIG. 1which requires no complex and extensive toggle mechanism to insureproper closure of the switch contact when the handle link 48 is moved tothe contact closed position.

It is apparent from the above that the present invention provides animproved circuit breaker construction incorporating a snap switchfeature. Through the use of a snap switch it is possible to use thecircuit breaker of FIG. 1 both as an over current protector and a powercurrent switch. By providing snap closure and snap opening of thecircuit breaker contacts, higher currents may be manually switched. Atthe same time, the simplified snap switch feature makes possible the useof a simpler and less expensive collapsible toggle mechanism foractuating the movable contact of the breaker. Also disclosed is amodified construction in which the circuit breaker is in an inexpensivemanner converted into a simple switch by eliminating the over currentconstruction including the coil and armature and substituting for thecollapsible toggle a single rigid link. Because of the completecompatibility of this switch construction with the overall circuitbreaker construction it is further possible by the present invention tocom bine independent elements with separate circuit breaking andswitching functions into a single package, preferably of modularconstruction. The snap switch feature is brought about by a simplifiedover center single toggle spring construction in combination with amechanism actuated carrier. Thus, the present invention provides animproved circuit breaker, switch and housing assembly possessing a wideversatility to suit the desires of the user. If desired, the individualmodules may be sold separately and readily and simply assembled into thepackage of FIG. 14 for example by the user as he desires. The frictionpins and recesses insure a reasonably permanent assembly and incombination with the end plates present a fully cooperative modularconstruction and one which is of a pleasing appearance.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are, therefore, to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are, therefore, intended to be embracedtherein.

What is claimed is:

l. A circuit breaker comprising a support, an overcurrent sensor on saidsupport, a collapsible toggle coupled to said sensor and adapted to, betripped by said sensor in response to an overcurrent, a movable carriercoupled to said toggle and movable between first and second positions inresponse to movement of said toggle, a contact movably mounted on saidcarrier and movable between open and closed positions, and an overcenterspring coupling said movable contact to 10 said support for moving saidcontact between said open and closed positions with a snap action inresponse to movement of said carrier by said toggle. I

2. A circuit breaker according to claim 1 wherein said overcurrentsensor comprises an overcurrent coil and armature.

3. A circuit breaker according to claim 1 wherein said toggle comprisesa pair of telescoping links.

4. A circuit breaker according to claim 1 wherein said toggle comprisesa pair of pivotally joined links.

5. A circuit breaker according to claim 1 wherein said toggle comprisesa pair of relatively movable links, said links being held againstrelative movement by a rotatable sear pin.

6. A circuit breaker according to claim 5 wherein said sear pin includesa cut away portion whereby rotation of said sear pin releases said linksfor relative movement.

7. A circuit breaker according to claim 1 including a contact bar, saidmovable contact being on said contact bar and said overcenter springacting on said contact bar.

8. A- circuit breaker according to claim 7 wherein said carrier isrotatable, and means pivotally supporting said contact bar on saidcarrier.

9. A circuit breaker according to claim 8 wherein said movable contactis mounted adjacent one end of said contact bar, said contact bar beingpivotally mounted on said carrier adjacent its other end.

,(s mano- Pnizxr. OFFICE '1 v h a 7 T CERTIFLCAiE OH CQRRLCTLOR Patent210. 3,806,848 mama April 23, 1974 O Inventor) George S. Harper and JohnRichard Shand It is certified that error appears in the above-identifiedpatent and that said Letters Patent are hereby corrected as shown below:

. The name of the assignee Airpax Erectronics Incorporatefi should beincluded in the above identified patent.

. Signed and sealed this 22nd day of October 1974.

v (SEAL) Attest:

McCOY M. GIBSON: JR. Attesting- Officer c. MARSHALL lfiANN Commissionerof Patents is PJJB T CFFZCE 5 ID-ZZTIQS-L'Ai CERTKFIQXTE 0 F CORRECTEQNEatent 21m 3,806,8 4 23 m d r-i1 23, 1974.

e It is certified that errnr appears in the above-ddentlfled patent andthat said Letters Patent are hereby corrected as shown below:

. The name of the assignee w Air ax Electrsnics lrmor fiffitd M J shouldbe included in the above identified gatemto Signed and sealed this 22ndday of October 197 (SEAL) Attest:

- McCOY M. GIBSONLJR. c. MARSHA-LL IDJANN -Attesting-OfficerCummissioner of Patents

1. A circuit breaker comprising a support, an overcurrent sensor on saidsupport, a collapsible toggle coupled to said sensor and adapted to betripped by said sensor in response to an overcurrent, a movable carriercoupled to said toggle and movable between first and second positions inresponse to movement of said toggle, a contact movably mounted on saidcarrier and movable between open and closed positions, and an overcenterspring coupling said movable contact to said support for moving saidcontact between said open and closed positions with a snap action inresponse to movement of said carrier by said toggle.
 2. A circuitbreaker according to claim 1 wherein said overcurrent sensor comprisesan overcurrent coil and armature.
 3. A circuit breaker according toclaim 1 wherein said toggle comprises a pair of telescoping links.
 4. Acircuit breaker according to claim 1 wherein said toggle comprises apair of pivotally joined links.
 5. A circuit breaker according to claim1 wherein said toggle comprises a pair of relatively movable links, saidlinks being held against relative movement by a rotatable sear pin.
 6. Acircuit breaker according to claim 5 wherein said sear pin includes acut away portion whereby rotation of said sear pin releases said linksfor relative movement.
 7. A circuit breaker according to claim 1including a contact bar, said movable contact being on said contact barand said overcenter spring acting on said contact bar.
 8. A circuitbreaker according to claim 7 wherein said carrier is rotatable, andmeans pivotally supporting said contact bar on said carrier.
 9. Acircuit breaker according to claim 8 wherein said movable contact ismounted adjacent one end of said contact bar, said contact bar beingpivotally mounted on said carrier adjacent its other end.